Editing Chemical equilibrium (section)

==Types of equilibrium==
{{Quote box|title=[[Haber–Bosch process]]
|quote=<div>
# N<sub>2</sub> (g) {{eqm}} N<sub>2</sub> [[Adsorption|(adsorbed)]]
# N<sub>2</sub> (adsorbed) {{eqm}} 2&nbsp;N (adsorbed)
# H<sub>2</sub> (g) {{eqm}} H<sub>2</sub> (adsorbed)
# H<sub>2</sub> (adsorbed) {{eqm}} 2&nbsp;H (adsorbed)
# N (adsorbed) + 3&nbsp;H(adsorbed) {{eqm}} NH<sub>3</sub> (adsorbed)
# NH<sub>3</sub> (adsorbed) {{eqm}} NH<sub>3</sub> (g)
</div>
}}
Equilibrium can be broadly classified as heterogeneous and homogeneous equilibrium.<ref>{{Cite web|url=https://www.chemguide.co.uk/physical/equilibria/kc.html|title = Equilibrium constants – Kc}}</ref> Homogeneous equilibrium consists of reactants and products belonging in the same phase whereas heterogeneous equilibrium comes into play for reactants and products in different phases.   
* In the gas phase: [[rocket engine]]s<ref name="nasa">{{cite web|publisher=NASA |series=NASA Reference publication 1311|last1=Gordon|first1=Sanford|last2=McBride|first2=Bonnie J. |date=1994 |url=https://www.grc.nasa.gov/WWW/CEAWeb/RP-1311.pdf |archive-url=https://web.archive.org/web/20060421143635/http://www.grc.nasa.gov/WWW/CEAWeb/RP-1311.pdf |url-status=dead |archive-date=2006-04-21 |title=Computer Program for Calculation of Complex Chemical Equilibrium Compositions and Applications}}</ref>
* The industrial synthesis such as [[ammonia]] in the [[Haber–Bosch process]] (depicted right) takes place through a succession of equilibrium steps including [[adsorption]] processes
* [[Atmospheric chemistry]]
* Seawater and other natural waters: [[chemical oceanography]]
* Distribution between two phases
** [[Partition coefficient|log ''D'' distribution coefficient]]: important for pharmaceuticals where lipophilicity is a significant property of a drug
** [[Liquid–liquid extraction]], [[Ion exchange]], [[Chromatography]]
** [[Solubility equilibrium|Solubility product]]
** Uptake and release of oxygen by [[hemoglobin]] in blood
* Acid–base equilibria: [[acid dissociation constant]], [[hydrolysis]], [[buffer solution]]s, [[pH indicator|indicators]], [[acid–base homeostasis]]
* Metal–ligand complexation: [[Chelation|sequestering agents]], [[chelation therapy]], [[Magnetic resonance imaging|MRI contrast reagents]], [[Schlenk equilibrium]]
* Adduct formation: [[host–guest chemistry]], [[supramolecular chemistry]], [[molecular recognition]], [[dinitrogen tetroxide]]
* In certain [[oscillating reaction]]s, the approach to equilibrium is not asymptotically but in the form of a damped oscillation .<ref name="CEM"/>
* The related [[Nernst equation]] in electrochemistry gives the difference in electrode potential as a function of redox concentrations.
* When molecules on each side of the equilibrium are able to further react irreversibly in secondary reactions, the final product ratio is determined according to the [[Curtin–Hammett principle]].

In these applications, terms such as stability constant, formation constant, binding constant, affinity constant, association constant and dissociation constant are used. In biochemistry, it is common to give units for binding constants, which serve to define the concentration units used when the constant's value was determined.